If you are using DCC, I’ve had some success with the NCE BD-2s, however, for a crossing signal, I would go with an Arduino and optical detectors. (Which would work for 2 or 3 rail, DC, AC, or DCC) Arduinos microcontrollers are less than $10 and two photoresistors $1 and you are in business. The catch is you would have to write a program for the Arduino - not hard, but if you don’t have experience with this, there would be a learning curve. The great thing about the Arduino is you can adjust everything easily by changing a few numbers in your code - adjust the detectors for ambient lighting of your room, the timing of the flashers, time delay before and after etc. Wiring is simple. One of my long-term projects at Cherry Valley is an Arduino signaling system using the Atlas PRR aspect signals. Atlas wired these signals backwards, intentionally I’m guessing, so you would have to buy their detectors and controllers. The LEDs are wired in a way that won’t work with traditional logic circuitry or Arduinos, however, adding a transistor (remember those things) in the right place will overcome this. I also planned on setting up an Arduino for a crossing signal at Cherry Valley some day, and could probably walk you through it if you wanted to give it a shot. Jim
